I've really gotten into shmuping lately, and have enjoyed going throught the xenocide files. I've even aquired some saturn shmups and a Twin astro city stick for my shmuping

Anyway, there's a couple of somewhat tecnical issues I've been pondering lately, and as I know nothing about technical matters I better consult "the knowing"...
Here goes. Lately I had a chance to tjeck out a few shmups played throught a chipped xbox and running on the emulator fbaXXX. The games were DoDonpachi, Guwange and battle Garegga.
When playing DoDonpachi on xbox, it seemed to run very much like the Saturn version. Except it had a lot more slowdowns. (and the explosions were much nicer) My questions are:
1. Does the Xbox play these games (Donpaachi, Dodonpachi, Guwange, Batsugun etc.) exactly like they would play on real arcade hardware?
2.Do the arcade versions have these slowdowns, but the saturn versions do not? I've gathered that this can be the case for some ports..
3. Also tecnically if an original arcade game infact does have some slowdowns, would an emulator not emulate these slowdowns?
4. Couldn't it also not be the case that there could be some slowdown when the xbox emulates these games, which do not acure on arcade hardware, but which are do to the xbox strugling with the task of emulating? which I understand is pretty draining of processing power.
5. I've newer seen Guwange played on arcade hardware, so I dont know what that looks like. But seing it being played on the xbox was very awesome looking to me. I wonder if this is Arcade perfect?
Well, I'm really not tech savy and have been thinking about these things lately, so I hope some of you knowlegeable people will explain to me..
Thanks